Filter Cap Additive Delivery System

ABSTRACT

A additive delivery system and method which includes a additive gel, a filter and a fluid/gel chemistry exchange region, wherein the exchange region subjects the additive gel to different types or combinations of contact with the fluid in order to control the additive release rate, maintain a uniform release rate, maintain the physical integrity of the gel or combinations thereof.

FIELD OF THE INVENTION

The present invention relates to additive delivery systems for allowinga fluid, such as oil, to come into contact with an additive gel to causeone or more additive components in the gel to be slowly released intothe fluid.

BACKGROUND OF THE INVENTION

Specially formulated slow-release additives that provide for the slowrelease of additives into a fluid such as oil to meet certainperformance requirements of the fluid are generally known. In some, theadditives are incorporated into thermoplastic polymers which slowlydissolve into the fluid. In others, the additives are incorporated intopolymers which are oil-permeable at elevated temperatures. In stillothers, the additives are incorporated into particles which arefluid-insoluble but fluid-wettable. In still others, fluid soluble solidpolymers are provided, with or without additional additives beingincorporated into the polymers.

Although these slow-release additives are capable of introducingadditives in the fluid being conditioned, it has been discovered thatadditive gels can be used more effectively to provide for the slowrelease of additives into a fluid, such as lubricant additives into oil.In particular, it has been found that fluid-soluble additive gels slowlydissolve to their component additive parts when contacted by the fluid.Examples of such additive gels are disclosed in U.S. Pat. No. 6,483,916,filed Jul. 16, 2002, U.S. patent applications Ser. No. 10/603,644, filedJun. 25, 2003, U.S. Ser. No. 10/603,894, filed Jun. 25, 2003 and U.S.Ser. No. 10/603,517, filed Jun. 25, 2003, which are incorporated hereinby reference.

Garvin et al, U.S. Pat. No. 7,000,655, discloses an additive deliverysystem which includes a container for the additive gel wherein thecontainer has one or more openings to allow contact of the fluid withthe gel to cause one or more additive components in the gel to bereleased into the fluid and the container is located in a housing with ameans of mounting the housing between the filter and the filter mountingsurface.

Burrington et al, U.S. Pat. No. 6,843,916, discloses an oil filtercomprising a housing, a filter for removing particulate matter from theoil passing through the filter, and oil-soluble lubricant additivesinside the housing for slow release into the oil.

Although these additive delivery systems are capable of introducingadditives into the fluid being conditioned, attaining a specific releaserate of components while maintaining physical gel integrity is acritical feature for a practical controlled release gel system. Improperand/or non-uniform release rates may result in less than optimalperformance of the fluid being conditioned and lack of physical gelintegrity can result in particles of gel breaking off of the larger gelmass present in the controlled release system. These gel fragments arecarried by the fluid and may plug filters and engine orifices, which maynegatively impact the overall performance of the fluid-utilizing systemor device.

Some applications have unique fluid flow characteristics through thefluid system, filter and any additive delivery system present. Thesefluid flow characteristics, which include fluid pressure, temperatureand flow rate, can interfere with an additive delivery system, resultingin undesired or non-optimal additive release rates and a loss in gelintegrity, leading to problems discussed above. Diesel passenger cars inparticular tend to have oil system flow characteristics that interferewith existing additive delivery systems.

There is a need for additive delivery systems that allow for the desiredcontact of the fluid with these additive gels, to cause one or morecomponents of the additives in the gels to be slowly released into thefluid, wherein the desired and/or uniform release rate of components isachieved while maintaining physical gel integrity. There is also a needfor additive delivery systems that provides the desired controlledrelease of one or more additives in systems with various fluid flowcharacteristics, including those seen in the oil system of dieselpassenger cars.

SUMMARY OF THE INVENTION

The present invention involves delivery systems for supplying one ormore additives to a fluid by allowing the contact of a fluid with anadditive gel, causing one or more components of the additives in the gelto be slowly released into the fluid, wherein the desired and/or uniformrelease rate of components is achieved while maintaining physical gelintegrity.

In accordance with one aspect of the invention, the additive deliverysystem comprises an additive gel, a filter having a housing, and afluid/gel chemistry exchange region located outside of the region of thefilter housing that experiences the direct flow of the fluid where thefluid contacts the gel.

In accordance with another aspect of the invention, the exchange regionof the system may allow for fluid/gel contacting comprising a) indirectfluid flow, b) direct fluid flow, or c) combinations thereof. Theexchange region may be selected so as to control the release rate ofadditives from the additive gel into the fluid, to maintain a uniformrelease rate of additives, to maintain the physical integrity of theadditive gel, or combinations thereof.

In accordance with another aspect of the invention, the system maycomprise a filter gel cap that contains the gel, wherein the filter gelcap is mountable and removable from the crown of the filter housing,wherein the filter housing has one or more openings on the crown of thefilter that allow fluid to pass from the filter, contact the additivegel and return to the filter. The number, size, shape, orientation,location, pattern, or combinations thereof of the openings on the crownof the filter housing may be selected so as to control and maintain thedesired additive gel component release rate and additive gel physicalintegrity.

In accordance with another aspect of the invention, the cap of thefilter housing may comprise an annular space along the outer wall of thefilter cap housing, wherein the annular space is created by the outerwall of the filter cap housing body and an interior wall that forms acylinder within the filter cap, wherein the interior wall connects tothe outer wall on one end and is open on the other, and wherein theadditive gel is placed within the annular space, whereby the fluid comesinto contact with the additive gel in the filter by passing over theopen end of the interior wall, contacting the additive gel in theannular space and passing back over the wall to the interior of thefilter. The filter cap with the gel-containing annular space may have amountable and removable lid that allows for direct access to thegel-containing annular space. The interior wall that forms the annulargel-containing space may contain one or more openings that allow fluidto pass from the filter housing into the annular space and contact theadditive gel, and wherein the number, size, shape, orientation,location, pattern, or combinations thereof of the openings are utilizedto control and maintain the desired additive gel component release rateand additive gel physical integrity.

In accordance with another aspect of the invention, the filter may be acartridge filter that is mounted inside a canister type housing that hasinlet and outlet passages for permitting fluid to flow through thehousing and around the cartridge.

In accordance with another aspect of the invention, the delivery systemmay be used to condition the fluid in devices comprising internalcombustion engines, natural gas engines, stationary engines, metalworking coolant systems, industrial lubricated systems, oil or fuelfilters, hydraulic systems, or transmission systems.

In accordance with another aspect of the invention, the filter may be anoil filter and the fluid may be engine lubricating oil, and the deviceutilizing the filter may be a diesel passenger car engine.

In accordance with another aspect of the invention, the system may beused as part of a method for releasing additives into a fluid comprisingoperating a device that utilizes a fluid.

In accordance with another aspect of the invention, the system can bethe filter cap that contains a fluid additive gel, which can be mountedonto a fluid filter in such a way as to allow a fluid to pass betweenthe filter and the cap, wherein the filter cap, when mounted onto saidfilter, contains a fluid/gel chemistry exchange region located outsidethe interior region of the filter that experiences the direct flow ofthe fluid, where the fluid contacts the gel.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more readily understood by reference to thefollowing drawings in which:

FIG. 1 is an exploded schematic longitudinal section view through oneform of additive delivery system of the present invention including afilter additive gel cap and filter housing cap, where the additive gelis present in the filter gel cap, where the filter gel cap fastens tothe filter housing cap, such that when the assembly is used in anoperating system, the assembly allows for the fluid that passes throughthe filter to pass through the openings in the filter housing cap andcome into contact with the additive gel inside the filter gel cap.

FIG. 1 a is a schematic longitudinal section view through one form ofadditive delivery system of the present invention in an assembled statewith fluid flow indicators.

FIG. 1 b is a perspective view of one embodiment of the additivedelivery system of the present invention in an assembled state.

FIG. 2 is a sectional perspective view of one embodiment of the filteradditive gel cap without the additive gel shown.

FIG. 3 is a sectional perspective view of one embodiment of the filterhousing cap for use with the filter additive gel cap.

FIG. 4 is an exploded schematic longitudinal section view through oneform of additive delivery system of the present invention including afilter additive gel cap and filter housing cap, where the additive gelis present in the filter gel cap, where the filter gel cap fastens tothe filter housing cap, such that when the assembly is used in anoperating system, the assembly allows for the fluid that passes throughthe filter to pass through the openings in the filter housing cap andcome into contact with the additive gel.

FIG. 4 a is a schematic longitudinal section view through one form ofadditive delivery system of the present invention in an assembled statewith fluid flow indicators.

FIG. 4 b is a perspective view of one embodiment of the additivedelivery system of the present invention in an assembled state.

FIG. 5 is a sectional perspective view of one embodiment of the filteradditive gel cap without the additive gel shown.

FIG. 6 is a sectional perspective view of one embodiment of the filterhousing cap for use with the filter additive gel cap.

FIG. 7 is an exploded schematic longitudinal section view through oneform of additive delivery system of the present invention including acombination filter additive gel cap and filter housing cap, where theadditive gel is present in the combination filter additive gel cap andfilter housing cap in an annular space, where the combination filteradditive gel cap and filter housing cap comprises two parts, a body partand a lid part, where the lid can be removed to allow for moreconvenient insertion of the additive gel into the annular space, suchthat when the assembly is used in an operating system, the assemblyallows for the fluid that passes through the filter to come into contactwith the additive gel.

FIG. 7 a is a schematic longitudinal section view through one form ofadditive delivery system of the present invention in an assembled statewith fluid flow indicators.

FIG. 7 b is a perspective view of one embodiment of the additivedelivery system of the present invention in an assembled state.

DETAILED DESCRIPTION

The additive delivery systems of the present invention provide for thedesired contact of a fluid being conditioned with an additive gel tocause one or more components of the additives in the gel to be slowlyreleased into the fluid as described hereafter wherein the desiredand/or uniform release rate of the one or more components is achievedwhile maintaining the physical integrity of the additive gel. Theadditive delivery systems of the present invention can be used tocondition the fluid in any lubricated mechanical systems or devicesincluding but not limited to those in internal combustion engines, suchas, but not limited to, diesel passenger car engines, natural gasengines, stationary engines, metal working coolant systems, industriallubricated systems, oil or fuel filters, hydraulic systems andtransmission systems and the like. The additive delivery system of thepresent invention provides the desired release rate and maintains gelintegrity under various fluid flow characteristics in the fluid systemand filter. These fluid flow characteristics include, but are notlimited to, fluid pressure, temperature and flow rate. This improvedperformance, across applications with varying fluid flow characteristicsin the applications' fluid system and filters, is achieved through thedesign of the additive delivery systems of the present invention.

In one embodiment of the additive delivery systems of the presentinvention the system comprises a fluid/gel chemistry exchange regionwhere the gel and fluid come into contact with one another to allow forthe release of additives from the additive gel into the fluid. Theexchange region may allow for contact that subjects the additive gel todirect fluid flow, where direct fluid flow is fluid flow at the point ofcontact with the additive gel at the flow rate, direction, pressure,temperature, and the like, which is near or about the maximum valuereached by the fluid in the filter for one or more of the parameterslisted. The exchange region may allow for contact that subjects theadditive gel to indirect fluid flow, where indirect fluid flow is fluidflow at the point of contact with the additive gel at a flow rate,direction, pressure, temperature, and the like, which is below themaximum value reached by the fluid in the filter for one or more of theparameters listed. Indirect flow regions may be created by placing theadditive gel in a nearly enclosed region of the filter or outside thefilter body as well as other means. The exchange region may also allowfor combinations of these types of contact. This combination of exchangeregions allows for the systems of the present invention to be customizedto the additive release needs of the various applications, includingapplications with extreme or unusual flow characteristics in the filter.

In one embodiment the exchange region can experience less than fulldirect flow, that is some amount of indirect flow. In another embodimentthe ratio of direct flow to indirect flow, by volume, in the exchangeregion can be between 5:95 and 95:5, between 10:90 and 90:10, or between25:75 and 75:25. In another embodiment the ratio of direct flow toindirect flow, by volume, in the exchange region can be between 5:95 and60:40, between 10:90 and 50:50, or between 15:85 and 45:55.

In one embodiment the additive delivery systems of the present inventioncontain the additive gel within a gel filter cap which attaches to theouter body of a filter whereby the additive gel is located outside ofthe filter housing and is not located in the direct flow areas of thefluid that passes through the filter. In one embodiment of the presentinvention, the filters used in the additive delivery systems of thepresent invention may be cartridge filters and the fluid may belubricating oil.

Examples of additive gels which may be used with the present inventionare disclosed in U.S. Pat. No. 6,483,916, filed Jul. 16, 2002, U.S.patent applications Ser. No. 10/603,644, filed Jun. 25, 2003, U.S. Ser.No. 10/603,894, filed Jun. 25, 2003 and U.S. Ser. No. 10/603,517, filedJun. 25, 2003, which are incorporated herein by reference.

Referring now in detail to the drawings, wherein the same referencenumbers are used to designate like parts, and initially to FIG. 1, thereis shown one form of a additive delivery system 1 in accordance with thepresent invention, including an additive gel filter cap 2 which may bemounted onto, and removed from, a filter housing cap 3 where the filterhousing cap 3 connects to a filter body housing (not shown) whichincludes a filter media (not shown) to form a complete filter, such asan oil filter. The filter housing cap 3 is shown with external threading17 along its bottom edge where the filter housing body would haveinternal threading and the filter housing cap 3 would fasten to thefilter housing body by spinning the filter housing cap 3 so the externalthreads 17 interface with the internal threads of the filter housingbody. The filter housing cap 3 may have a filter media fastening device18 located on the inside surface opposite of the surface that mountsonto the filter using device. This fastening device may be in the formof a circular clip that is used to secure a filter media insert (notshown) in the filter housing cap. The filter media insert may connect tothe filter housing cap 3 by snapping onto the fastening device 18 or bysimilar means. This type of removable and replaceable filter mediainsert is commonly used in cartridge type filters. The filter housingcap 3 may also be part of a complete, single piece filter (not shown),where the filter housing cap cannot be separated from the rest of thefilter housing, but is a single piece.

The additive gel filter cap 2 may include a bolt head 5 on the crown ofthe additive gel filter cap 2, such as a hex bolt head, to allow fortools, such as wrenches, to interface with the gel filter cap 2. Thefilter housing cap 3 may also include a bolt head 12 on the crown of thefilter housing cap, such as a hex bolt head.

The additive gel filter cap 2 may include a bolt head socket 7, locatedon the inside surface of the additive gel filter cap 2 opposite of theend with the mounting surface for the filter using device, which restson and interfaces with the filter housing cap 3 when the gel filter cap2 is mounted on the filter housing cap 3. More specifically, the bolthead socket 7 of the additive gel filter cap 2, may interface with thebolt head 12 of the filter housing cap 3, creating an interface thatallows the effect of tools on the bolt head of the additive gel filtercap 5 to be transferred to the bolt head 12 of the filter housing cap 3.For example, where the bolt head on the crown of a filter is utilized toinstall the filter onto a larger device, such as an internal combustionengine, the interface created by the additive gel filter cap's bolt headsocket 7 allows the bolt head on the additive gel filter cap to beutilized in the same manner for the filter installation.

The additive gel filter cap 2 contains the additive gel 4 in theinterior void space 9 of the additive gel filter cap 2 between andaround the bolt head socket 7 and the side wall 8 of the additive gelfilter cap 2, as shown in FIG. 1. The additive gel 4 may be placed inthe interior void space 9 prior to the additive gel filter cap 2 beingmounted onto the filter housing cap 3. The additive gel 4 may bedispensed into the interior void space 9 whereby the components of thegel may be mixed within the space such that the gelformation/manufacturing occurs within the additive gel filter cap 2, orthe additive gel 4 may be pre-formed into a shape or shapes that allowsthe gel to be inserted into the interior void space 9 of the additivegel filter cap 2. The additive gel 4 may be further contained in one ormore gel containers, packages or gel cups (not shown) that may beinserted into the interior void space 9 of the additive gel filter cap2. The gel cup or cups, or other containers, may be removable, allowingthe gel cup to be removed and replaced or refilled with gel, and placedin another additive gel filter cap 2 for additional use. A removable gelcup may also allow a used filter to be serviced, either after removalfrom the apparatus or device it is used with or while still connected tosuch an apparatus or device, by removing the additive gel filter cap 2from the filter housing cap 3 and then removing the used gel cup andreplacing it with a new gel cup with a new supply of additive gel 4. Thegel cup may have openings of various sizes and shapes to allow for thecontact of the fluid with the additive gel 4 present in the gel cup.

The filter housing cap 3 may be a standard filter housing cap used witha filter housing body and filter media to form a conventional filterwhere modifications are made after the initial filter manufacturing inorder to make the filter housing cap 3 compatible with the additive gelfilter cap 2. The filter housing cap 3 may also be specially designed towork with an additive gel filter cap 2. The filter housing cap 3 mayhave one or more openings 13 located on the crown of the housing capthat allow for fluid, when a filter gel cap 2 is mounted onto thehousing cap 3, to pass from the interior of the filter cap 14, throughthe openings 13 in the filter housing cap 3 and into the additive gelfilter cap's interior void space 9, where the fluid comes into contactwith the additive gel 4, and then passes through the openings 13 in thefilter housing cap 3 and back into the interior of the filter cap 14 andthe rest of the filter (not shown).

The filter housing cap openings 13 may be one or more circular holes, asshown in FIG. 1, that allow for fluid to travel across the filterhousing cap 3. The housing cap openings 13 may be of various sizes andshapes, including but not limited to circles, ovals, slits or mixturesthereof and may be arranged symmetrically or randomly on the filterhousing cap 3. The openings 13 may also be so large as to effectivelyencompass the entire crown of the filter cap, leaving only the filtermedia insert support 18 and some means connecting the support 18 to aremaining rim of the filter housing cap 3 where the rim may include thehousing cap's side exterior wall 16 and everything below it. Theopenings 13 may be arranged such that the axis passing through thecenter of the openings are parallel to the vertical axis of the filterhousing cap 3. The openings 13 may be also be arranged such that theaxis passing through the center of the openings are at an angle to thevertical axis of the filter housing cap 3. The openings 13 may be partof the filter design and fabrication or the openings 13 may be createdafter the filter is manufactured.

The flow characteristic of the fluid as it contacts the additive gel 4can be controlled and by modifying the orientation, size, shape,arrangement, location and combinations thereof of the openings 13 in thefilter housing cap 3. Modifying one or more of these parameters relatedto the housing cap's openings 13 modifies the amount of surface area ofthe additive gel 4 contacted by the fluid passing through the additivegel filter cap 2; modifies the flow rate, flow direction, fluid pressureand other fluid flow characteristics of the fluid passing through theadditive gel filter cap 2; or combinations thereof. This control offluid flow characteristic allows for the additive delivery systems ofthe present invention to provide the desired additive gel componentrelease rate while maintaining additive gel integrity in a wide varietyof applications.

In addition, the inner surface of the additive gel filter cap's sidewall 8 may have an undercut, grade, reduction or similar geometricfeature to create a flow path for the fluid around the additive gel 4and/or to help keep the additive gel 4 secure and intact within the voidspace 9 of the additive gel filter cap 2.

The additive gel filter cap 2 mounts onto the filter housing cap 3whereby the additive gel filter cap 2 slides over filter housing cap 3such that the bottom edge 11 of the side wall 8 of the additive gelfilter cap 2 rests in an outer lip 15 that runs around the outside ofthe filter housing cap 3 below all of the openings 13 in the filterhousing cap 3 and above the external threads 17 of the filter housingcap 3. The additive gel filter cap 2 may also include a seal cavity 10which may be in the form of a annular space carved out of the lowerinside surface of the side wall 8, forming a ring cavity that allows forthe use of an o-ring or similar seal (not shown) in the seal cavity 10.The use of a seal in the seal cavity 10 can act to provide a sealbetween the additive gel filter cap 2 and the filter housing cap 3 wherethe seal in the seal cavity 10 contacts the filter housing cap exteriorwall surface 16 when the additive gel filter cap 2 is mounted on thefilter housing cap 3.

The additive gel filter cap 2 may also be secured to the filter housingcap 3 by means of a bolt or similar fastening device. The bolt, orsimilar device, may be placed through the center of the filter housingcap 3 through a hollow shaft 22 in the bolt head 12 on the crown of thehousing cap 3. The bolt may then interface with threads on the walls ofa similar shaft 6 in the center of the additive gel cap 2 therebyfastening the additive gel cap 2 onto the filter housing cap 3.

FIG. 1 a shows a cross section diagram of the present invention wherethe additive gel filter cap 2 and the filter housing cap 3 are in anassembled state, where the additive gel filter cap 2 is mounted on crownof the filter housing cap 3 and the arrows indicate the flow of thefluid being conditioned through the system. The filter body housing 19and the filter media 20 are also shown. FIG. 1 b shows an explodedperspective view of the present invention. The same labels are used toidentify the various features of the embodiments shown in FIGS. 1, 1 aand 1 b, unless otherwise noted.

In FIG. 1 a the arrows indicate how the fluid from the device with whichthe filter is being used may flow within the filter, and morespecifically how the fluid may flow within the filter housing cap 3,pass through the openings 13 in the filter housing cap 3 and into theadditive gel filter cap 2 where the fluid comes into contact with theadditive gel 4 and then passes back through the openings 13 in thefilter housing cap 3, into the filter housing cap 3 and back to thedevice as filtered and conditioned fluid.

The fluid flowing through the filter housing body 19 will pass through afilter element 20 which may be fabricated of any suitable filteringmedium and will return the fluid to the device. The fluid, as shown inFIG. 1 a, will also pass into the additive gel filter cap 2 where thefluid will come into contact with the additive gel 4 and then return tothe filter housing cap 3 and the filter housing 19. This controlled flowof fluid across the additive gel 4 results in a controlled dissolutionof the additive components of the additive gel 4 into the fluid whilemaintaining the physical integrity of the additive gel 4. The presentinvention allows gels of various formulations, including relatively softgels that would otherwise: 1) release additive components too quickly,2) release additive components at non-uniform rates, 3) completelydissolve before the end of a desired service cycle, 4) be broken up intogel fragments that would be carried by the fluid and potentially blockdevice lines and orifices, or 5) combination thereof, to be used moreeffectively and in a wider range of applications without these issues.

FIG. 2 is a sectional perspective view of one embodiment of the filteradditive gel cap where no additive gel is present and FIG. 3 is aperspective view of one embodiment of the filter housing cap. Theidentifying features of the embodiments shown in FIG. 2 and FIG. 3 aresimilar to those described in FIG. 1, FIG. 1 a and FIG. 1 b and areidentified by the same labels.

Another embodiment of the present invention is shown in FIG. 4, wherethe additive delivery system 31 includes an additive gel filter cap 32which may be mounted onto a filter housing cap 33 where the filterhousing cap 33 connects to a filter body housing (not shown) to form acomplete filter, such as but not limited to an oil filter. While FIG. 4shows one embodiment of the present invention and FIG. 1 shows anotherembodiment, many of the same features are present in both, and where agiven feature is present in both embodiments, the description providedabove in regards to FIG. 1 also applies to the embodiment shown in FIG.4 unless otherwise noted.

The filter housing cap 33 in FIG. 4 is shown with external threading 47along its bottom edge where the filter housing body (not shown) wouldhave internal threading and the filter housing cap 33 would fasten tothe filter housing body (not shown) by spinning the filter housing cap33 so the external threads 47 interface with the internal threads of thefilter housing body (not shown). The filter housing cap 33 may have afilter media insert fastening device 52 similar to the media fasteningdevice 18 in FIG. 1 that allows filter media inserts to connect to thefilter housing cap 33.

Similar to the embodiment of the present invention shown in FIG. 1, theembodiment of the present invention may include a bolt head (not shown)on the crown of the filter housing cap 33. The present invention mayalso include, as shown in FIG. 4, an opening 42 on the crown of thefilter housing cap 33 where the opening 42 allows for a bolt 51 orsimilar device to be used to secure the additive gel filter cap 32 tothe filter housing cap 33 by allowing the bolt 51 to pass through theopening 42 on the crown of the filter housing cap and into a shaft 36 inthe additive gel filter cap 32. The shaft 36 may have threads thatinterface with the bolt 51, thus securing the additive gel filter cap 32to the filter housing cap 33. The filter additive gel cap 32 may alsoinclude a bolt head 35 on the crown of the filter housing cap, such as ahex bolt head or square bolt head.

The additive gel filter cap 32 may include a bolt head socket (notshown), located inside the additive gel filter cap 32, which rests onand interfaces with the filter housing cap 33. More specifically, thebolt head socket (not shown) of the additive gel filter cap 32, mayinterface with a bolt head socket (not shown) of the filter housing cap33 or may rest on the crown of the filter housing cap 33.

The additive gel filter cap 32 contains the additive gel 34 in theinterior void space 39 of the additive gel filter cap 32 between andaround any bolt head socket (not shown) and the side walls 38 of theadditive gel filter cap 32, as shown in FIG. 4. The additive gel 34 maybe placed in the additive gel filter cap's interior void space 39 in thesame manners described above in regards to the embodiment of theinvention shown in FIG. 1.

The filter housing cap 33 may be a standard filter housing cap used withmodifications made after the initial filter manufacturing in order tomake the filter housing cap 33 compatible with the additive gel filtercap 32. The filter housing cap 33 may also be specially designed to workwith an additive gel filter cap 32. The filter housing cap 33 may haveone or more openings 43 located on the crown of the filter housing cap33 that allow for fluid, when the cap is assembled as a filter with anadditive gel filter cap 32, to pass from the interior of the filterhousing cap 44, through the openings 43 in the filter housing cap 33 andinto the additive gel filter cap's interior void space 39, where thefluid comes into contact with the additive gel 34, and then passesthrough the openings 43 in the filter housing cap 33 and back into theinterior of the filter housing cap 44 and the rest of the filter (notshown).

The filter housing cap openings 43 may be varied in the same waysdescribed above in regards to the embodiment of the invention shown inFIG. 1, and more specifically, in regards to the openings 13 in thefilter housing cap 3 shown in FIG. 1. Varying the parameters related tothe openings 43 has the same impact as described above, specificallycontrolling the flow characteristics of the fluid as it contacts theadditive gel 34. This control of fluid flow characteristic allows forthe additive delivery systems of the present invention to provide thedesired additive gel component release rate while maintaining additivegel integrity in a wide variety of applications.

The additive gel filter cap 32 mounts onto the filter housing cap 33whereby the additive gel filter cap 32 slides over the filter housingcap 33 such that the bottom edge 41 of the side wall 38 of the additivegel filter cap 32 rests in an outer lip 45 that runs around the outsideof the filter housing cap 33 below all of the openings 43 in the filterhousing cap 33 and above the external threads 47 of the filter housingcap 33.

The filter housing cap's outer lip 45 may have an outer wall 53 thatcreates a wall around the outer edge of the lip 45. This outer wall maycreate a circular well between the filter housing cap lip 45, the filterhousing cap exterior wall surface 46, and the lip's outer wall 53, inwhich the bottom edge 41 of the additive gel filter cap 32 sits when theadditive gel filter cap 32 is mounted to the filter housing cap 33.

The outer wall 53 may have one or more openings 52 that allow for theuse of one or more screws, pins or other similar items (not shown),where the screws of other similar items are used to further secure theadditive gel filter cap 32 to the filter housing cap 33. This securingis accomplished wherein the additive gel filter cap 32 is mounted on thefilter housing cap 33 such that the bottom surface 41 of the additivegel filter cap 32 is resting on the outer lip 45 of the filter housingcap, set screws, or other similar items, can be inserted in the openings52 in the lip's outer wall 53 such that the screws are secured to thewall 53 and press against the additive gel filter cap's outer side walls38, causing the inner surface of the ring 54 created by the bottomsurface 41 of the additive gel filter cap 32 to be pressed against theouter wall 46 of the filter housing cap 33, and thereby holding theadditive filter cap 32 in place.

The filter housing cap 33 may also have a sealing cavity or groove 40around its circumference where the sealing groove 40 may be located inthe exterior surface 46 of the filter housing cap 33 just above thehousing cap's outer lip 45. The sealing groove 40 may also act tofurther secure the additive gel filter cap 32 to the filter housing cap33 where, when the additive gel filter cap 32 is being mounted onto thefilter housing cap 33, the ring-like inside surface 54 of additive gelfilter cap 32, created by the gel cap's bottom surface 41, slides downalong the filter housing cap's outer wall 46 and is inserted in thesealing groove 40 of the filter housing cap 40. If sized appropriately,the additive gel filter cap 32 and the filter housing cap 33 would snaptogether with the gel cap's inside ring surface 54 locking into thefilter housing cap's sealing groove 40. The sealing groove 40 may alsocontain an o-ring or similar sealing device (not shown) to form a sealbetween the filter housing cap 33 and the gel cap 32.

FIG. 4 a shows a cross section diagram of the present invention wherethe additive gel filter cap 32 and the filter housing cap 33 are in anassembled state, where the additive gel filter cap 32 is mounted on thecrown of the filter housing cap 33 and the arrows indicate the flow ofthe fluid being conditioned through the system. The filter body housing49 and filter media 50 are also shown. FIG. 4 b shows a perspective viewof the present invention. The same labels are used to identify thevarious features of the embodiments shown in FIGS. 4, 4 a and 4 b,unless otherwise noted.

In FIG. 4 a the arrows indicate how the fluid from the device with whichthe filter is being used may flow within the filter, and morespecifically within the filter housing cap 33, pass through the openings43 in the filter housing cap 33 and into the additive gel filter cap 32where the fluid comes into contact with the additive gel 34 and thenpasses back through the openings 43 in the filter housing cap 33, intothe filter housing cap 33 and back to the device as filtered andconditioned fluid.

The fluid flowing through the filter housing body 49 will pass through afilter element 50 which may be fabricated of any suitable filteringmedium and will return the fluid to the device. The fluid, as shown inFIG. 4 a, will also pass into the additive gel filter cap 32 where thefluid will come into contact with the additive gel 34 and then return tothe filter housing. This indirect flow of fluid across the additive gel34 located in the additive gel filter cap 32 results in the controlleddissolution of the additive components of the additive gel 34 into thefluid while maintaining the physical integrity of the additive gel.

FIG. 5 is a sectional perspective view of one embodiment of the filteradditive gel cap without gel present and FIG. 6 is a sectionalperspective view of one embodiment of the filter housing cap. Theidentifying features of the embodiments shown in FIG. 5 and FIG. 6 aresimilar to those described in FIG. 4, FIG. 4 a and FIG. 4 b and areidentified by the same labels.

Another embodiment of the present invention is shown in FIG. 7, wherethe additive delivery system 61 includes an additive gel filter capwhich may be an integrated part of a filter housing cap. In thisembodiment, the filter housing cap and filter cap are in the form of anintegrated part that contains the additive gel 78 and connects to thefilter body housing (not shown) to form a filter.

While FIG. 7 shows one embodiment of the present invention and FIG. 1and FIG. 4 show other embodiments, many of the same features are presentall of the figures and where a given feature is present in more than oneembodiment, the descriptions provided above in regards to theembodiments shown in FIG. 1 and FIG. 4 also apply to the embodimentshown in FIG. 7 unless otherwise noted.

The integrated filter gel cap 61 of the present invention may be asingle piece that attaches to a filter body housing (not shown) just asa conventional filter housing cap would, utilizing interlocking threadsor a similar fastening means. The integrated filter gel cap 61 of thepresent invention may also be made up of two distinct parts, a lid 62and a body 63 where the lid 62 may be removed from the body 63 to allowfor better access to the annular space 74 that holds the additive gel78. The lid 62 may have internal threading 69 on the inside of itsbottom edge 70 used to connect it to the body 63. The body 63 may haveexternal threading 72 on the outside of its upper edge 71 used toconnect the body 63 to the lid 62. The lid 62 and the body 63 may beconnected by placing the threads, 69 and 72, in contact with one anotherand spinning the lid 62 to engage the threads into one another.

The integrated gel filter cap body 63 in FIG. 7 is shown with externalthreading 76 along its bottom edge where the filter housing body (notshown) would have internal threading and the integrated gel filter capbody 63 would fasten to the filter housing body (not shown) by spinningthe integrated gel filter cap body 63 so the external threads 76interface with the internal threads of the filter housing body (notshown).

The integrated gel filter cap lid 62 may have a filter media insertfastening device 67 similar to the media fastening device 18 in FIG. 1that allows filter media inserts to connect to the integrated gel filtercap lid 62.

Similar to the embodiment of the present invention shown in FIG. 1, theembodiment of the present invention shown in FIG. 7 may include a bolthead 65 on the crown of the integrated gel filter cap lid 62.

The integrated gel filter cap 61 contains the additive gel 78 in theinterior annular void space 74 of the integrated gel filter cap body 63between the integrated gel filter cap body's outer wall 79 and its innerwall 75. This annular space 74 can be adjusted to hold various amountsof additive gel 78 based on the dimensions of the integrated gel filtercap 61 and specifically the integrated gel filter cap body 63. Theadditive gel 78 may be placed in the integrated gel filter cap'sinterior annular void space 74 in the same manners described above inregards to the embodiment shown in FIG. 1. The ability to remove theintegrated gel filter cap lid 62 from the integrated gel filter cap body63 allows for additional options of inserting the additive gel 78.

The integrated gel filter cap body's interior wall 75 may have an inwardcurve that acts as a diverter edge or similar feature at its upper edge73 as shown in FIG. 7. This diverter edge 73 acts to affect the flowcharacteristics present in a filter when it is fully assembled with theintegrated filter gel cap 61. Specifically, the geometry of theintegrated gel filter cap's body's internal wall 75 and its diverteredge 73 can affect the amount of contact between the additive gel 78 andthe fluid passing through the filter (not shown) as well as the flowrate, direction of flow relative to the additive gel 78 and pressure ofthe fluid during the contact. The integrated gel filter cap's body'sinternal wall 75 may also have one or more openings (not shown) locatedalong the wall between the interior void space 77 that encloses thefilter media insert (not shown) and the annular space 74 that containsthe additive gel 78. These openings (not shown) may allow for fluid,when the integrated cap is assembled and used as a filter, to pass fromthe interior of the filter cap 77, through the openings in theintegrated gel cap body's interior wall 75 and contact the additive gel78 contained in the annular space 74. The fluid may contact the additivegel 78 at the openings and remain within the interior of the filterhousing 77 or it may pass through the openings into the annular space74, contacting the additive gel 78 during this period, and travel up tothe interior wall's upper edge 73, where the fluid then returns to theinterior space of the filter housing 77 and continues to pass throughthe filter.

The integrated gel filter cap interior wall openings (not shown) may beone or more circular holes, and may also be of various sizes and shapes,including but not limited to circles, ovals, slits or mixtures thereofand may be arranged symmetrically or randomly on the integrated gelfilter cap's interior wall 75. The openings may be arranged such thatthe axis passing through the center of the openings are perpendicular tothe plane of the interior wall 75. The openings may be also be arrangedsuch that the axis passing through the center of the openings are at anangle to the plane of the interior wall 75.

The flow characteristic of the fluid as it contacts the additive gel 78can be controlled and by modifying the orientation, size, shape,arrangement, location and combinations thereof of the openings in theintegrated gel filter cap body 63 and/or by modifying the geometry ofthe integrated gel filter cap's interior wall 75 and upper edge 73.Modifying one or more of these parameters modifies the amount of surfacearea of the additive gel 78 contacted by the fluid passing through theintegrated gel filter cap 61; modifies the flow rate, flow direction,fluid pressure and other fluid flow characteristics of the fluid passingthrough the integrated gel filter cap 61; or combinations thereof. Thiscontrol of fluid flow characteristic allows for the additive deliverysystems of the present invention to provide the desired additive gelcomponent release rate while maintaining additive gel integrity in awide variety of applications.

FIG. 7 a is a schematic longitudinal section view through one form ofadditive delivery system of the present invention in an assembled statewhich may also represent the present invention when the integratedfilter gel cap lid and body are fixed and cannot be separated. Thearrows indicate the flow of the fluid being conditioned through thesystem. The filter body housing 81 and the filter media 82 are alsoshown. FIG. 7 b shows a perspective view of the present invention. Thesame labels are used to identify the various features of the embodimentsshown in FIGS. 7, 7 a and b, unless otherwise noted.

FIG. 7 a shows a cross section diagram of the present invention wherethe integrated gel filter cap lid 62 and the integrated gel filter capbody 63 are in an assembled state, where the integrated gel filter caplid 62 is mounted on crown of integrated gel filter cap body 63 and thearrows indicate the flow of the fluid being conditioned through thesystem. The filter body housing 81 and filter media 82 are also shown.

In FIG. 7 a the arrows indicate how the fluid from the device with whichthe filter is being used may flow within the filter, and morespecifically within the integrated gel filter cap 61, as the fluid maypass through the filter housing interior 77, pass through the openingsin the integrated gel filter cap's interior wall 75 and/or pass over theupper edge 73 of the interior wall 75, and into the annular space 74containing the additive gel 78 where the fluid comes into contact withthe additive gel 78 and then passes back through the openings in theintegrated gel filter cap's interior wall 75 and/or passes over theupper edge 73 of the interior wall 75 and back to the filter housingspace 77 and ultimately the connected device as filtered and conditionedfluid.

The fluid flowing through the filter housing body 81 will pass through afilter element 82 which may be fabricated of any suitable filteringmedium and will return the fluid to the device. The fluid, as shown inFIG. 7 a, will also pass into the integrated gel filter cap's additivegel containing annular space 74 where the fluid will come into contactwith the gel 78 and then return to the filter housing. This indirectflow of fluid across the additive gel 78 located in the annular space 74will result in the controlled dissolution of the additive components ofthe additive gel 78 into the fluid while maintaining the physicalintegrity of the additive gel. The present invention allows gels ofvarious formulations, including relatively soft gels that wouldotherwise release additive components too quickly, release additivecomponents at non-uniform rates, completely dissolve before the end of adesired service cycle, be broken up into gel fragments that would becarried by the fluid and potentially block device lines and orifices, orcombination thereof to be used more effectively and in a wider range ofapplications.

The identifying features of the embodiments shown in FIG. 7 a aresimilar to those described in FIG. 7 and are identified by the samelabels.

EXAMPLE

Into a container of the style shown in FIG. 7 and FIG. 7 a, two equallyspaced rows of 6 holes in each row, each hole measuring 5 mm indiameter, are drilled into the annular space wall. Into the annularspace is placed a mixture of the following composition:

TABLE 1 Composition of Additive Gel Percent by Weight Component 13.2%Olefin copolymer viscosity modifier 47.8% diluent mineral oil 2.4%ashless polyisobutylene succinic anhydride dispersant maleic anhydridestyrene 9.6% copolymer, partially esterified 100.0% TOTAL

The mixture is heated at 100C for 8 hours to form a gel. The tilledadditive gel filter cap is mounted onto a cartridge-style filter mediainsert and this assembly is fit into a cartridge-style filter housing,thus providing an additive delivery system of the present invention.

The assembled filter cartridge and housing is placed on a dynamometerequipped with a PSA DV6 engine and run for 100 hours. At the end of thetest, oil analysis shows that an amount of viscosity modifier equivalentto and increase in 0.4 cSt has been released into the oil compared to abaseline in which a standard filter with no additive gel present.

Although only a few embodiments of the present invention have beendescribed above, it should be appreciated that many modifications can bemade without departing from the spirit and scope of the invention. Allsuch modifications are intended to be included within the scope of thepresent invention, which is to be limited only by the following claims.

1. A delivery system for supplying one or more additives to a fluidcomprising an additive gel, a filter having a housing, and a fluid/gelchemistry exchange region located outside of the region of the filterhousing that experiences the direct flow of the fluid where the fluidcontacts the gel.
 2. The system, of claim 1 wherein the exchange regionallows for fluid/gel contacting which comprises: a) indirect fluid flow,b) direct fluid flow, or c) combinations thereof.
 3. The system of claim1 where the exchange region is selected so as to control the releaserate of additives from the additive gel into the fluid, to maintain auniform release rate of additives, to maintain the physical integrity ofthe additive gel, or combinations thereof.
 4. The system of claim 1wherein the system comprises a filter gel cap that contains the gel,wherein the filter gel cap is mountable and removable from the crown ofthe filter housing, wherein the filter housing has one or more openingson the crown of the filter that allow fluid to pass from the filter,contact the additive gel and return to the filter.
 5. The system ofclaim 4 wherein the number, size, shape, orientation, location, pattern,or combinations thereof of the openings on the crown of the filterhousing are selected so as to control and maintain the desired additivegel component release rate and additive gel physical integrity.
 6. Thesystem of claim 1 wherein the cap of the filter housing comprises anannular space along the outer wall of the filter cap housing, whereinthe annular space is created by the outer wall of the filter cap housingbody and an interior wall that forms a cylinder within the filter cap,wherein the interior wall is connects to the outer wall on one end andis open on the other, and wherein the additive gel is placed within theannular space, whereby the fluid comes into contact with the additivegel in the filter by passing over the open end of the interior wall,contacting the additive gel in the annular space and passing back overthe wall to the interior of the filter.
 7. The system of claim 6 whereinthe filter cap with the gel-containing annular space has a mountable andremovable lid that allows for direct access to the gel-containingannular space.
 8. The system of claim 6 wherein the interior wall thatforms the annular gel-containing space contains one or more openingsthat allow fluid to pass from the filter housing into the annular spaceand contact the additive gel, and wherein the number, size, shape,orientation, location, pattern, or combinations thereof of the openingsare utilized to control and maintain the desired additive gel componentrelease rate and additive gel physical integrity.
 9. The system of claim8 wherein the interior wall that forms the annular gel-containing spaceforms an upper lip that acts as a diverter edge, wherein the diverteredge is designed to affect the fluid flow around the edge and so intothe gel-containing annular space.
 10. The system of claim 1 wherein theadditive gel is contained within a gel cup, wherein one or more gel cupsmay be inserted into and removed from the system, the gel cup having oneor more openings to allow contact of the fluid that passes through thefilter with the gel.
 11. The system of claim 8 wherein at least some ofthe openings in the interior wall of the annular space are unobstructedby the additive gel inside the space so as to allow some of the fluid toenter the annular space through the openings and dissolve one or moreadditive components in the gel.
 12. The system of claim 8 furthercomprising a fluid flow diverter edge at the open end of the interiorwall that forms the gel-containing annular space, wherein the diverteredge acts to divert the flow of the fluid passing through the filter andnear the opening of the annular gel-containing space, providing controlover the gel/fluid chemistry exchange region.
 13. The system of claim 1wherein the filter is a cartridge filter that is mounted inside acanister type housing that has inlet and outlet passages for permittingfluid to flow through the housing and around the cartridge.
 14. Thesystem of claim 1 wherein the delivery system is used to condition thefluid in devices comprising internal combustion engines, natural gasengines, stationary engines, metal working coolant systems, industriallubricated systems, oil or fuel filters, hydraulic systems, ortransmission systems.
 15. The system of claim 1 wherein the filter is anoil filter and the fluid is engine lubricating oil.
 16. The system ofclaim 15 wherein the device utilizing the filter is a diesel passengercar engine.
 17. A method for releasing additives into a fluid comprisingoperating a device that utilizes a fluid, wherein the device utilizesthe system of claim
 1. 18. A filter cap that contains a fluid additivegel which can be mounted onto a fluid filter in such a way as to allow afluid to pass between the fluid filter and the filter cap, wherein thefilter cap, when mounted onto said filter, contains a fluid/gelchemistry exchange region located outside of the region of the interiorof the filter that experiences the direct flow of the fluid, where thefluid contacts the gel.